In packaging applications, it may be desirable to seal a film package without the use of a separate adhesive film layer on the package. Such a sealing process can be performed by using materials that can be self-adhered, or materials that can be made to adhere to or to adhere to another material. One such process is a process by which radio frequency (RF) energy is applied to a suitable material, and after absorption of the RE energy the material can subsequently be self-adhered, or adhered to different substrates to form a seal. This process is known as RE welding, and suitable materials for such a process are known in commercial practice. Polyvinyl chloride (PVC), for example, is a material that can be susceptible to RF energy and be very suitable for RF welding. PVC, however, is not an acceptable material for widespread use in some areas of the world and alternate materials are needed to perform the function of PVC in those regions where PVC is not desirable.
Selecting suitable alternate materials for use in packaging applications that use the RF welding technique is not a trivial exercise. In selecting or developing suitable alternative materials, at least three (3) criteria need to be met. First, the material must provide good physical and/or mechanical characteristics that are satisfactory for a package or a component thereof. Second, a suitable polymer film should be susceptible to, that is should absorb, RF energy. Third, the polymer film should be capable of forming a bond, weld, or seal, when subjected to RF energy under the proper conditions of pressure and time.
Accordingly, it would be desirable to provide a composition that absorbs RE energy, and can be sealed using RE welding, while yet having physical and mechanical properties suitable for use in packaging applications.
Numerous applications are known in which a gas and vapor barrier film is incorporated in articles to prevent the transmission of gases and vapors to thereby control or prevent the loss of freshness and flavor and/or the escape of aroma or odor. In some applications, including medical and health care applications, it is desirable that the barrier film be relatively quiet and not emit noise upon deflecting or otherwise moving the film. For example, this is a prime objective for materials used in ostomy pouches or similar products worn under a person's clothing.
In an attempt to provide films with high barrier properties with low noise characteristics, artisans have used polyvinylidene chloride or SARAN″-coated films. However, those materials contain chlorine and thus are difficult and/or costly to recycle. Furthermore, films that contain polyvinylidene chloride cannot be incinerated without generating toxic gas. Accordingly, it would be desirable to provide a halogen-free film that exhibited high barrier and low noise properties, to provide a suitable replacement for currently known halogen containing films such as the noted chlorine containing materials.